Chester Vase: Sir Dragonet among Derby favourites after win for Aidan O'Brien

Sir Dragonet is among the leading contenders for the Derby at Epsom next month after giving trainer Aidan O'Brien a ninth Chester Vase victory.

The 13-2 shot, ridden by the trainer's son Donnacha, went clear of stablemate Norway (9-2) to win by eight lengths, with Dashing Willoughby in third.

Sir Dragonet, a son of O'Brien's 2012 Derby winner Camelot, needs to be added as a supplementary entry for Epsom.

But bookmakers cut his odds to around 6-1 joint-second favourite.

That puts the Chester winner alongside Saturday's 2,000 Guineas winner Magna Grecia, who won for the same jockey-trainer combination, and just behind John Gosden's 4-1 favourite Too Darn Hot.

"He was very impressive," said the winning jockey. "To be honest, I think it's the first time I've sat on him.

"Four furlongs out, I knew I was going to win. If he was entered in the Derby, he would certainly be worth his place."

Mehdaahiy, a daughter of Frankel, emerged as another Classic contender for trainer Gosden after winning the Cheshire Oaks under Rab Havlin.

The filly, who beat Manuela De Vega by four-and-a-half lengths, will also need to be added as a supplementary entry if she is to run in the Oaks at Epsom on 30 May.

BBC horse racing correspondent Cornelius Lysaght

Early May is crucial for trying to solve the Derby puzzle as Aidan O'Brien shuffles his cards and looks to rank his challengers for a Classic that he's backed strongly.

The weekend trials at Lingfield and Leopardstown have regularly been informative, but he's become very keen on races at tiny 'turning' Chester as a good test of a horse's athleticism.

Sir Dragonet passed his examination with flying colours, considering it was only his second race, and though not entered at Epsom, after this highly impressive performance, he's sure to be added when that can be done for £85,000.